Large vehicles such as semitrailer trucks may easily travel several thousand miles each month, including on highways and other routes which allow for higher speeds. Poor aerodynamics cause a decrease in fuel economy and an increase in operating cost.
Various types of aerodynamic systems have been devised for reducing vehicle drag, including fairings—that is, external panels or structures added to vehicles to increase streamlining and reduce drag—that are positioned to control airflow. U.S. Pat. Nos. 9,027,983 and 9,663,157, both of which are fully incorporated herein by reference for all purposes, describe aerodynamic fairing systems that include a quarter fender fairing assembly, a middle or tandem fairing assembly and a rear fairing assembly. The quarter fender fairing assembly mounts forward of the truck tractor's non-steered wheels, the tandem (or middle) fairing assembly mounts to the tractor between the tandem wheels and the rear fairing assembly mounts to the tractor behind the rear tandem wheels. Each fairing assembly includes a mounting arm that mounts to the tractor frame and one or more panels that mount to the support arm. The panels are shaped to produce a desired aerodynamic flow.
In practice, the manner in which fairings mount to support arms leaves the mounting hardware exposed when the vehicle is viewed from the side. In addition to poor aesthetics, the exposed mounting hardware may lead to poor airflow at the mounting hardware. As another shortcoming, the mounting hardware may get damaged over time by road debris.